PURPOSE: To omit the removal step of a conductive film by etching the conductive film using a resist-pattern as a mask according to a dry-etching method to form the conductive pattern, thereby using the conductive pattern as a part of the optical element.
CONSTITUTION: The guide 2 is formed on a substrate 1, and then a SiO2 buffer layer is provided on said guide 2 followed by forming a corning glass layer on the prescribed buffer layer to form the optical waveguide 2. The transparent conductive film 3 having a suitable dry-etching properties is formed at the prescribed range on the optical waveguide 2 of the substrate 1 followed by coating an electron beam resist 4 on the prescribed film 3. And then, a coupler pattern 4a of the resist is formed on the prescribed resist 4 according to an electron beam lithography. Finally, the coupler pattern 3a composed of the conductive film is obtd. by etching the conductive film 3 using the resist pattern 4a as the mask according to the dry-etching process. Thus, the pattern 3a composed of the transparent conductive film remains on the optical waveguide 2, thereby completing the grading coupler 5 loaded a transparent conductive film thereon.
HANADA KEIJI
YAMASHITA MAKI
